/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Diagnostics;
using System.Collections;
using System.Text;
using System.IO;
using PdfSharp.Internal;
using PdfSharp.Pdf.Advanced;
using PdfSharp.Pdf.IO;
using System.Collections.Generic;

namespace PdfSharp.Pdf
{
  /// <summary>
  /// Represents a PDF array object.
  /// </summary>
  [DebuggerDisplay("(elements={Elements.Count})")]
  public class PdfArray : PdfObject, IEnumerable
  {
    ArrayElements elements;

    /// <summary>
    /// Initializes a new instance of the <see cref="PdfArray"/> class.
    /// </summary>
    public PdfArray()
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="PdfArray"/> class.
    /// </summary>
    /// <param name="document">The document.</param>
    public PdfArray(PdfDocument document)
      : base(document)
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="PdfArray"/> class.
    /// </summary>
    /// <param name="document">The document.</param>
    /// <param name="items">The items.</param>
    public PdfArray(PdfDocument document, params PdfItem[] items)
      : base(document)
    {
      foreach (PdfItem item in items)
        Elements.Add(item);
    }

    /// <summary>
    /// Initializes a new instance from an existing dictionary. Used for object type transformation.
    /// </summary>
    /// <param name="array">The array.</param>
    protected PdfArray(PdfArray array)
      : base(array)
    {
      if (array.elements != null)
        array.elements.SetOwner(this);
    }

    /// <summary>
    /// Creates a copy of this array. Direct elements are deep copied. Indirect references are not
    /// modified.
    /// </summary>
    public new PdfArray Clone()
    {
      return (PdfArray)Copy();
    }

    /// <summary>
    /// Implements the copy mechanism.
    /// </summary>
    protected override object Copy()
    {
      PdfArray array = (PdfArray)base.Copy();
      if (array.elements != null)
      {
        array.elements = array.elements.Clone();
        int count = array.elements.Count;
        for (int idx = 0; idx < count; idx++)
        {
          PdfItem item = array.elements[idx];
          if (item is PdfObject)
            array.elements[idx] = item.Clone();
        }
      }
      return array;
    }

    /// <summary>
    /// Gets the collection containing the elements of this object.
    /// </summary>
    public ArrayElements Elements
    {
      get
      {
        if (this.elements == null)
          this.elements = new ArrayElements(this);
        return this.elements;
      }
    }

    /// <summary>
    /// Returns an enumerator that iterates through a collection.
    /// </summary>
    public virtual IEnumerator GetEnumerator()
    {
      return Elements.GetEnumerator();
    }

    /// <summary>
    /// Returns a string with the content of this object in a readable form. Useful for debugging purposes only.
    /// </summary>
    public override string ToString()
    {
      StringBuilder pdf = new StringBuilder();
      pdf.Append("[ ");
      int count = Elements.Count;
      for (int idx = 0; idx < count; idx++)
        pdf.Append(Elements[idx].ToString() + " ");
      pdf.Append("]");
      return pdf.ToString();
    }

    internal override void WriteObject(PdfWriter writer)
    {
      writer.WriteBeginObject(this);
      int count = Elements.Count;
      for (int idx = 0; idx < count; idx++)
      {
        PdfItem value = Elements[idx];
        value.WriteObject(writer);
      }
      writer.WriteEndObject();
    }

    /// <summary>
    /// Represents the elements of an PdfArray.
    /// </summary>
    public sealed class ArrayElements : IList, ICloneable
    {
      ArrayList elements;
      PdfArray owner;

      internal ArrayElements(PdfArray array)
      {
        this.elements = new ArrayList();
        this.owner = array;
      }

      object ICloneable.Clone()
      {
        ArrayElements elements = (ArrayElements)MemberwiseClone();
        elements.elements = (ArrayList)elements.elements.Clone();
        elements.owner = null;
        return elements;
      }

      /// <summary>
      /// Creates a shallow copy of this object.
      /// </summary>
      public ArrayElements Clone()
      {
        return (ArrayElements)((ICloneable)this).Clone();
      }

      /// <summary>
      /// Moves this instance to another dictionary during object type transformation.
      /// </summary>
      internal void SetOwner(PdfArray array)
      {
        this.owner = array;
        array.elements = this;
      }

      /// <summary>
      /// Converts the specified value to boolean.
      /// If the value not exists, the function returns false.
      /// If the value is not convertible, the function throws an InvalidCastException.
      /// If the index is out ouf range, the function throws an ArgumentOutOfRangeException.
      /// </summary>
      public bool GetBoolean(int index)
      {
        if (index < 0 || index >= Count)
          throw new ArgumentOutOfRangeException("index", PSSR.IndexOutOfRange);

        object obj = this[index];
        if (obj == null)
          return false;
        if (obj is PdfBoolean)
          return ((PdfBoolean)obj).Value;
        else if (obj is PdfBooleanObject)
          return ((PdfBooleanObject)obj).Value;
        throw new InvalidCastException("GetBoolean: Object is not a boolean.");
      }

      /// <summary>
      /// Converts the specified value to integer.
      /// If the value not exists, the function returns 0.
      /// If the value is not convertible, the function throws an InvalidCastException.
      /// If the index is out ouf range, the function throws an ArgumentOutOfRangeException.
      /// </summary>
      public int GetInteger(int index)
      {
        if (index < 0 || index >= Count)
          throw new ArgumentOutOfRangeException("index", PSSR.IndexOutOfRange);

        object obj = this[index];
        if (obj == null)
          return 0;
        if (obj is PdfInteger)
          return ((PdfInteger)obj).Value;
        if (obj is PdfIntegerObject)
          return ((PdfIntegerObject)obj).Value;
        throw new InvalidCastException("GetInteger: Object is not an integer.");
      }

      /// <summary>
      /// Converts the specified value to double.
      /// If the value not exists, the function returns 0.
      /// If the value is not convertible, the function throws an InvalidCastException.
      /// If the index is out ouf range, the function throws an ArgumentOutOfRangeException.
      /// </summary>
      public double GetReal(int index)
      {
        if (index < 0 || index >= Count)
          throw new ArgumentOutOfRangeException("index", PSSR.IndexOutOfRange);

        object obj = this[index];
        if (obj == null)
          return 0;
        if (obj is PdfReal)
          return ((PdfReal)obj).Value;
        else if (obj is PdfRealObject)
          return ((PdfRealObject)obj).Value;
        else if (obj is PdfInteger)
          return ((PdfInteger)obj).Value;
        else if (obj is PdfIntegerObject)
          return ((PdfIntegerObject)obj).Value;
        throw new InvalidCastException("GetReal: Object is not a number.");
      }

      /// <summary>
      /// Converts the specified value to string.
      /// If the value not exists, the function returns the empty string.
      /// If the value is not convertible, the function throws an InvalidCastException.
      /// If the index is out ouf range, the function throws an ArgumentOutOfRangeException.
      /// </summary>
      public string GetString(int index)
      {
        if (index < 0 || index >= Count)
          throw new ArgumentOutOfRangeException("index", PSSR.IndexOutOfRange);

        object obj = this[index];
        if (obj == null)
          return "";
        if (obj is PdfString)
          return ((PdfString)obj).Value;
        if (obj is PdfStringObject)
          return ((PdfStringObject)obj).Value;
        throw new InvalidCastException("GetString: Object is not an integer.");
      }

      /// <summary>
      /// Converts the specified value to a name.
      /// If the value not exists, the function returns the empty string.
      /// If the value is not convertible, the function throws an InvalidCastException.
      /// If the index is out ouf range, the function throws an ArgumentOutOfRangeException.
      /// </summary>
      public string GetName(int index)
      {
        if (index < 0 || index >= Count)
          throw new ArgumentOutOfRangeException("index", PSSR.IndexOutOfRange);

        object obj = this[index];
        if (obj == null)
          return "";
        if (obj is PdfName)
          return ((PdfName)obj).Value;
        if (obj is PdfNameObject)
          return ((PdfNameObject)obj).Value;
        throw new InvalidCastException("GetName: Object is not an integer.");
      }

      /// <summary>
      /// Returns the indirect object if the value at the specified index is a PdfReference.
      /// </summary>
      [Obsolete("Use GetObject, GetDictionary, GetArray, or GetReference")]
      public PdfObject GetIndirectObject(int index)
      {
        if (index < 0 || index >= Count)
          throw new ArgumentOutOfRangeException("index", PSSR.IndexOutOfRange);

        PdfItem item = this[index];
        if (item is PdfReference)
          return ((PdfReference)item).Value;
        return null;
      }

      /// <summary>
      /// Gets the PdfObject with the specified index, or null, if no such object exists. If the index refers to
      /// a reference, the referenced PdfObject is returned.
      /// </summary>
      public PdfObject GetObject(int index)
      {
        if (index < 0 || index >= Count)
          throw new ArgumentOutOfRangeException("index", PSSR.IndexOutOfRange);

        PdfItem item = this[index];
        if (item is PdfReference)
          return ((PdfReference)item).Value;
        return item as PdfObject;
      }

      /// <summary>
      /// Gets the PdfArray with the specified index, or null, if no such object exists. If the index refers to
      /// a reference, the referenced PdfArray is returned.
      /// </summary>
      public PdfDictionary GetDictionary(int index)
      {
        return GetObject(index) as PdfDictionary;
      }

      /// <summary>
      /// Gets the PdfArray with the specified index, or null, if no such object exists. If the index refers to
      /// a reference, the referenced PdfArray is returned.
      /// </summary>
      public PdfArray GetArray(int index)
      {
        return GetObject(index) as PdfArray;
      }

      /// <summary>
      /// Gets the PdfReference with the specified index, or null, if no such object exists.
      /// </summary>
      public PdfReference GetReference(int index)
      {
        PdfItem item = this[index];
        return item as PdfReference;
      }

      /// <summary>
      /// Gets all items of this array.
      /// </summary>
      public PdfItem[] Items
      {
          get { return (PdfItem[])this.elements.ToArray(typeof(PdfItem)); }
      }

      /// <summary>
      /// INTERNAL USE ONLY.
      /// </summary>
      public ArrayList GetArrayList()
      {
        // I use this hack to order the pages by ZIP code (MigraDoc ControlCode-Generator)
        // TODO: implement a clean solution
        return this.elements;
      }

      #region IList Members

      /// <summary>
      /// Returns false.
      /// </summary>
      public bool IsReadOnly
      {
        get { return false; }
      }

      object IList.this[int index]
      {
        get { return this.elements[index]; }
        set { this.elements[index] = value; }
      }

      /// <summary>
      /// Gets or sets an item at the specified index.
      /// </summary>
      /// <value></value>
      public PdfItem this[int index]
      {
        get { return (PdfItem)this.elements[index]; }
        set
        {
          if (value == null)
            throw new ArgumentNullException("value");
          this.elements[index] = value;
        }
      }

      /// <summary>
      /// Removes the item at the specified index.
      /// </summary>
      public void RemoveAt(int index)
      {
        this.elements.RemoveAt(index);
      }

      void IList.Insert(int index, object value)
      {
        this.elements.Insert(index, value);
      }

      /// <summary>
      /// Inserts the item the specified index.
      /// </summary>
      public void Insert(int index, PdfItem value)
      {
        this.elements.Insert(index, value);
      }

      void IList.Remove(object value)
      {
        this.elements.Remove(value);
      }

      /// <summary>
      /// Removes the specified value.
      /// </summary>
      public void Remove(PdfItem value)
      {
        this.elements.Remove(value);
      }

      bool IList.Contains(object value)
      {
        return this.elements.Contains(value);
      }

      /// <summary>
      /// Determines whether the specified value is in the array.
      /// </summary>
      public bool Contains(PdfItem value)
      {
        return this.elements.Contains(value);
      }

      /// <summary>
      /// Removes all items from the array.
      /// </summary>
      public void Clear()
      {
        this.elements.Clear();
      }

      int IList.IndexOf(object value)
      {
        return this.elements.IndexOf(value);
      }

      /// <summary>
      /// Gets the index of the specified item.
      /// </summary>
      public int IndexOf(PdfItem value)
      {
        return this.elements.IndexOf(value);
      }

      int IList.Add(object value)
      {
        return this.elements.Add(value);
      }

      /// <summary>
      /// Appends the specified object to the array.
      /// </summary>
      public int Add(PdfItem value)
      {
        // TODO: ??? 
        //Debug.Assert((value is PdfObject && ((PdfObject)value).Reference == null) | !(value is PdfObject),
        //  "You try to set an indirect object directly into an array.");

        PdfObject obj = value as PdfObject;
        if (obj != null && obj.IsIndirect)
           this.elements.Add(obj.Reference);
        this.elements.Add(value);

        return elements.Count - 1;
      }

      /// <summary>
      /// Returns false.
      /// </summary>
      public bool IsFixedSize
      {
        get { return false; }
      }

      #endregion

      #region ICollection Members

      /// <summary>
      /// Returns false.
      /// </summary>
      public bool IsSynchronized
      {
        get { return false; }
      }

      /// <summary>
      /// Gets the number of elements in the array.
      /// </summary>
      public int Count
      {
        get { return this.elements.Count; }
      }

      /// <summary>
      /// Copies the elements of the array to the specified array.
      /// </summary>
      public void CopyTo(Array array, int index)
      {
        this.elements.CopyTo(array, index);
      }

      /// <summary>
      /// The current implementation return null.
      /// </summary>
      public object SyncRoot
      {
        get { return null; }
      }

      #endregion

      #region IEnumerable Members

      /// <summary>
      /// Returns an enumerator that iterates through the array.
      /// </summary>
      public IEnumerator GetEnumerator()
      {
        return this.elements.GetEnumerator();
      }

      #endregion
    }
  }
}
